The M1 rifle was the first semiautomatic rifle to be the standard
small arm of the US Military, and the first semiautomatic rifle
to be adopted by a major military power. It was the product of a
genuine genius, John Cantius Garand. While the M1 was never officially
referred to as the Garand, it is known by no other name so widely.
First adopted in 1936, the M1 Rifle served the US in World War II,
Korea, a host of "police actions" and interventions, and,
in the hands of allies, in the Vietnam War. Even there the US Army
fielded accurized sniper M1 rifles even though the M1 had by that
time been replaced by the M14 and later the M16.
The M1 Garand was in the words of General Patton "The greatest
battle implement ever devised."